1. Field of the Invention
The present invention relates to an air conditioning apparatus.
2. Description of the Related Arts
In recent years, there has been a growing demand for the development of an air conditioning apparatus capable of accomplishing favorable air-conditioning.
Most conventional air conditioning apparatuses of a heat pump type adopt a convection system. That is, in order to obtain a room temperature set by a user and maintain the obtained set room temperature, a heat exchanger of an indoor air conditioner transfers heat therefrom to room air and vice versa. Air cooled or heated is circulated in the room.
These conventional air conditioning apparatuses accomplishes a favorable air-conditioning in rise time in which the room temperature is much higher than the set temperature, namely, the comfortable temperature, namely, 24.degree. to 25.degree. C. in summer or much lower than the comfortable temperature, namely, 21.degree. to 22.degree. C. in winter, but may give discomfort to the user in the vicinity of the set temperature, namely, the comfortable temperature because the user is subjected to the flow of air cooled or heated for a long time.
Some conventional air conditioning apparatuses adopt radiant system of cooling or heating room air by cooling or heating the ceiling, the floor or the wall of the room.
The radiant system accomplishes a favorable air-conditioning in the vicinity of the set temperature; does not subject the user to the flow of air cooled or heated; and makes the temperature of the room air uniform.
But the radiant system has disadvantages in that a thermal load is great in rise time and it takes longer than convection system to attain the set temperature. In addition, the radiant system causes dew to be formed on the surface of a cooling radiant panel. That is, when air of a high temperature and a high humidity strikes the surface of the cooling radiant panel in summer, moisture in air is condensed to form water droplets thereon. For example, under the circumstances of a high temperature of 30.degree. C. and a high humidity of 60%, dew is formed on the surface of the cooling radiant panel, the temperature of which is 20.degree. C. Therefore, it is necessary to use a dehumidifier additionally so as to reduce the humidity when the indoor air is radiantly cooled. Dew is still formed thereon or the indoor air becomes too dry if the matching between the temperature of the dehumidifier and that of the cooling radiant panel is not appropriately controlled.